1. Field of the Invention
The invention relates to a method of stabilizing aqueous poly-2-oxazoline complexes with certain polyhalide ions by use of a lower alkanol in an amount sufficient to prevent loss of available halogen. The invention also relates to the compositions formed and a method of using the compositions as sanitizing agents.
2. Description of the Prior Art
Halophors have long been known and the art is replete with various classes of halophors, processes for their manufacture, and a myriad of their alleged utilities. See, for example, Disinfection, Sterilization and Preservation, 2nd Edition, Chapter 11, Lea & Febiger (Philadelphia 1977) by S. S. Block. Of the many known halophors, probably the most common are those prepared from iodine (I.sub.2) and polyvinylpyrrolidone. These materials are generally complexes of indefinite composition and are generally soluble in water. When solubilized, these complexes slowly liberate free iodine which is the active ingredient. These complexes can contain up to about 25 weight percent iodine although not all is available (titratable with Na.sub.2 S.sub.2 O.sub.3) due to some being organically bound to the polymr. Many patents have issued regarding these complexes and U.S. Pat. Nos. 4,017,407; 3,898,326; 3,028,300; 2,900,305; 2,826,532 and 2,739,922 are exemplary.
Halophors or complexes of polyoxazolines or polyoxazines and halogens, interhalogens and pseudo-halogens, are described in U.S. Pat. No. 4,144,211 to Chamberlin and Bangs. These complexes represent a class of halophors distinct from the complexes of polyvinylpyrrolidone and have demonstrated utility as sanitizing agents.
Halophor complexes of polyoxazolines or polyoxazines and polyhalide anions are described in our copending U.S. patent application Ser. No. 139,306 filed Apr. 11, 1980, which is a continuation-in-part of U.S. patent application Ser. No. 030,396 filed Apr. 16, 1979, both of which are hereby incorporated by reference.
These two applications describe water-soluble complexes, useful as sanitizing agents, comprising (a) a poly-2-oxazoline or poly-2-oxazine polymer; (b) a polyhalide anion of the formula (XY.sub.2n).sup.- where X and Y are individually chlorine, bromine or iodine, but not both chlorine, and n is 1, 2 or 3; and an independently supplied cation selected from the group consisting of alkali metals, alkaline earth metals, hydrogen and mixtures thereof. These materials are prepared at room temperature in either an aqueous or anhydrous environment and are significantly more stable than complexes of either poly-2-oxazoline or poly-2-oxazine and halogen, interhalogen or pseudo-halogen or complexes of polyvinylpyrrolidone and polyhalides. Certain species of these compositions may, however, degenerate upon aging. Degeneration is the loss of available halogen by chemical combination with other components of the composition or by formation of insoluble precipitates.
It is an object of this invention to obtain a composition which is degeneration inhibited in accelerated aging tests, which will form a solids-free solution which does not separate on standing.
It is a further object of this invention to provide a method for degeneration inhibiting complexes containing poly-2-oxazolines or poly-2-oxazines and certain polyhalide anions.
It is a still further object of this invention to provide a method for sanitizing substrates with a degeneration inhibited sanitizing complex.